Prognostic significance of peritoneal metastasis from colorectal cancer treated with first-line triplet chemotherapy

Table 1 Characteristics of 51 patients with metastatic colorectal cancer, with and without peritoneal metastasis treated with triplet chemotherapy

	Whole group	Peritoneal metastasis N (%)	No peritoneal metastasis N (%)	P value
Age in years	52 (23-74)	52 (23-74)	50 (32-73)	0.97
Gender				0.97
Male	27 (52.9%)	8 (53.3%)	19 (52.8%)
Female	24 (47.1%)	7 (46.7%)	17 (47.1%)
Site of primary				0.03
Left	40 (78.4%)	9 (60%)	31 (86.1%)
Right	11 (21.6%)	6 (40%)	5 (13.9%)
Performance status				0.8
0-1	40 (78.4%)	12 (80%)	28 (77.8%)
2	11 (21.6%)	3 (20%)	8 (22.2%)
Liver metastasis				0.01
Yes	33 (64.7%)	6 (40%)	27 (75%)
No	18 (35.3%)	9 (60%)	9 (25%)
Lung metastasis				0.07
Yes	20 (39.2%)	3 (20%)	17 (47.2%)
No	31 (60.8%)	12 (80%)	19 (52.8%)
KRAS status				0.14
Wild	20 (39.2%)	3 (20%)	17 (47.2%)
Mutant	21 (41.2%)	9 (60%)	12 (33.3%)
Unknown	10 (19.6%)	3 (20%)	7 (19.4%)
Prior surgery to primary				0.3
Yes	29 (55.9%)	10 (66.7%)	19 (52.8%)
No	22 (43.1%)	5 (33.3%)	17 (47.2%)
No of metastatic sites				0.39
1	19 (37.2%)	4 (28.6%)	13 (41.9%)
> 1	32 (62.7%)	10 (71.4%)	18 (58.1%)
Metastasectomy				0.4
Yes	13 (25.5%)	5 (33.3%)	8 (22.2%)
No	38 (74.5%)	10 (66.7%)	28 (77.8%)

Table 2 Univariate analysis of progression-free survival and overall survival in 51 patients with metastatic colorectal cancer treated with triplet therapy

	PFS		OS
	Mo (95% CI)	P value	Mo (95% CI)	P value
Age		0.034		0.157
< 65	12.4 (5-19.9)		31.3 (14.9-47.6)
≥ 65	5.7 (5-6.3)		20.9 (0-45.2)
Gender		0.429		0.439
Male	10.8 (4.3-17.3)		31.3 (13.2-49.3)
Female	9.4 (0-19.3)		29.1 (0-58.5)
Site of primary		0.823		0.844
Left	10.8 (4.1-17.5)		31.3 (14.8-47.7)
Right	9.1 (0.5-17.8)		20.9 (0-82.8)
Performance status		0.068		0.532
0-1	15.9 (7-24.8)		38.2 (22.9-53.5)
2	6.9 (2.8-11)		31.3 (5.7-56.8)
Liver metastasis		0.046		0.001
Yes	8.9 (7-10.9)		24.7 (10.9-38.5)
No	15.9 (5.7-26.1)		NR
Lung metastasis		0.011		0.087
Yes	8.9 (6.4-11.4)		24.7 (17.6-31.9)
No	13.7 (5.8-21.6)		40 (0-84.7)
Peritoneum metastasis		0.401		0.368
Yes	9.4 (8.6-10.1)		NR
No	13.7 (4.4-22.9)		31.3 (19.5-43.1)
KRAS		0.957		0.851
Wild	13.7 (0-30.7)		38.2 (23.3-53)
Mutant	10.8 (5.2-16.4)		29.1 (20.8-37.3)
Unknown	9.4 (8.2-10.5)		22.1 (0-44.4)
Prior surgery to primary		0.928		0.764
Yes	10.8 (3-18.6)		29.1 (23.7-34.4)
No	10.2 (3.4-17)		40 (14.8-65.2)
No of metastatic sites		0.565		0.278
1	12.4 (6.7-18.2)		61.7 (0-127.7)
> 1	8.9 (6.6-11.3)		27.6 (21.9-33.4)
Metastasectomy		0.001		0.002
Yes	18.6 (0-NR)		NR
No	8 (5.4-10.6)		27.6 (20.8-34.4)

PFS: Progression-free survival; OS: Overall survival; CI: Confidence interval; NR: Not reached.

Table 3 Multivariate analysis of progression-free survival and overall survival in 51 patients with metastatic colorectal cancer treated with triplet therapy

	PFS		OS
	HR (95%CI)	P value	HR (95%CI)	P value
Age		0.002
≥ 65	1a
< 65	0.22 (0.08-0.57)
Liver metastasis		0.076		0.003
Yes	1a		1a
No	0.5 (0.23-1.07)		0.21 (0.07-0.6)
Metastasectomy		0.001		0.005
Yes	1a		1a
No	0.23 (0.09-0.57)		0.18 (0.05-0.61)

^aRepresent the reference group.

PFS: Progression-free survival; OS: Overall survival; HR: Hazard ratio; CI: Confidence interval.